init: Fix typo.

Bug: 27681085
Change-Id: I4308435a5b58189852c991d1bec65ed11933566a
diff --git a/init/init.cpp b/init/init.cpp
index fb660eb..69f0595 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -353,7 +353,7 @@
             && set_mmap_rnd_bits_min(16, 16, true)) {
         ret = 0;
     }
-#elif defined(__x86__64__)
+#elif defined(__x86_64__)
     /* x86_64 supports 28 - 32 bits */
     if (set_mmap_rnd_bits_min(32, 32, false)
             && set_mmap_rnd_bits_min(16, 16, true)) {